Work clamp for folding machine



1956 G. o. SOMMERHALTER 2,759,726

WORK CLAMP FOR FOLDING MACHINE Filed Feb. 20, 1953 i Fi 5 INVENTOR.

. Gustav O. 'Jommerfia/fer BY ATTORNEYO WURK CL FQR lFvCDLlDlNG MACHENE Gustav (It. Summer-halter, Rochester, N. id, assignor to The American Laundry Machinery Company, Cincinnati, Uhio, a corporation of @hio Application February 20, 1953, Serial No. 337,916

3 Claims. (Cl. 27tl8tl) The invention relates to folding machines for cross folding fiat articles such as sheets, pillowcases, towels and the like. More specifically it relates to that type of folding machine wherein elongated folding means is movable back and forth across the path of article movement, whereby an article is draped back and forth over the folding means, and then delivered to folding rolls.

The invention particularly relates to the provision of novel and improved means for maintaining the draped article in fixed relationship on the swingable folding means while the latter is in the non-folding or rear portion of the oscillatory cycle.

In prior folding devices of the above described type clamping means of various kinds have been provided although none such means was entirely satisfactory. Some of the prior art clamps were biased against the folding blade in such a way that free movement of the blade during the folding stroke was hampered so as to injuriously aifect the accuracy of the folding operation. Other such clamps were subject to inertia shock or sharp impact during initial clamping contact, which also affected the folding operation in an undesired way.

An object of the present invention is to provide a clamping structure whereby the holding action is positive but is nevertheless applied by a gentle rolling movement with the least possible delaying effect on the motion of the folding blade.

A further object of the invention is to provide a clamping means such as is defined in the last preceding paragraph and wherein the direction of clamping contact is substantially normal to the plane of folding blade swing, to thereby reduce to a minimum any tendency to opposition to the blade swing.

Other objects and advantages will be apparent from a study of the following specification, in conjunction with the accompanying drawings.

Those engaged in designing, selling, or using laundry flatwork folding machines are familiar with the type of machine wherein an elongated folding blade is swingable back and forth across a vertical plane, so as to intersect said plane twice during a complete cycle of movement. If a fiatwork article is moving downwardly in said plane the first swing of the blade can be timed to intercept the article along a transverse line about at its one-quarter point or elsewhere and the return swing intercepts the article about at its three-quarter point, or otherwise. This return swing, if at the quarter points as described, introduces the one-quarter-three-quarter superposed fold lines between folding rolls which complete the folding operation.

For a detailed description of the operation of a folding machine of this nature the reader may refer to U. S. Patent No. 2,464,823, granted March 22, 1949, to Clifton S. Malott, Ir. For present purposes the operation will be briefly touched upon in conjunction with a description of the accompanying drawings, in which:

Fig. 1 is a side elevational View of a folding machine 2,759,726 Patented Aug. 21, 1%56 showing only such elements as are essential to an understanding of the present invention.

Fig. 2 is a greatly enlarged view of fragmentary details of the folding rolls, the folding blade, and the clamping device, showing in broken line the article to be folded, the blade being in its rearward or clamping position.

Fig. 3 is a fragmentary detail view taken from the right of Pig. 2.

Referring now to the drawings, and at first mainly to Fig. 1, workpieces are deposited on the top flight of conveyor tapes It), at the right end thereof. Considering the route of one such workpiece 9, it moves upwardly and to the left and around roll 11, its leading edge descending on the top flight of conveyor tapes 12, and to the right and downwardly thereon. Continuing, it proceeds between tapes 12 and 13, being carried thereby around roll 14, and then to the left again and over roll 15. As its leading edge travels counterclockwise around roll 15 it is directed downwardly by guide fingers l6, and the fiatwork article thereafter moves downwardly in a vertical plane tangential with roll 15.

Turning now to the folding mechanism it comprises a pair of co-acting folding rolls 17 and 18, a folding blade 19 carried by a lever arm 2i pivoted at 21, and a clamping means generally referred to by reference numeral 22. Lever 20 is of the first class, wherein motive force is applied at the point 23 by a link 24 responsive to movement of the rocker arm 95 which is pivoted at The rocker arm is biased to the Fig. 1 positioned by a compression spring 27 on a guide rod 28 which extends through an aperture in the frame portion 2%. The rocker arm 25 is periodically swung to the left, counterclockwise by the cam rise portion 30a of a rotary cam 31). Obviously, swing of the rocker arm 25 results in swing of the folding blade arm 20.

Timing means 33 is provided adjacent the path of travel of the article, being here shown adjacent tapes 12, and being sensitive to passage of the workpiece therepast, said timing means being operatively electrically connected to the operating mechanism for cam 3t so that folding blade arm 20, with its folding blade 39, is oscillated at suitable thnes to fold the workpiece along the proper transverse fold lines. Suitable time delay means is combined with the timing means so that progress of the workpiece to the proper folding position is permitted before operation of the folding blade. Various timing controls which function as just described are commercially available, and will not be more fully described herein since not essential for an understanding of the present invention.

Referring now to Fig. 2, the blade 19 is shown in its rearward position, having swung thereto from the broken line position adjacent the folding rolls 17 and 18. During such swing the leading one-quarter portion 9a of the workpiece 9 has been carried to the right, as shown, and the remainder of the workpiece begins to loop downwardly forming portions 912, which approximately correspond to the second and third one-quarter portions of the article, although not accurately so, at the moment pictured.

From a mere glance at Fig. 2 it is apparent that as the loop 9b-9c increases in length its weight tends to pull rearwardly oil blade 19 the portion 9a already draped thereon. It is therefore desirable that clamping means he provided to retain the draped portion a in contact with blade 19 at least until the blade again swings to the left and again intercepts the workpiece. This should be done at such time that the leading edge 1% of the blade will then underlie the one-quarter and three-quarter points on the workpiece, if this is the fold arrangement desired. The clamp should also be so arranged that it does not frictionally retard the swing of blade 19 towards light weight material with consequently little inertia.

I 3 the folding rolls 17 and 18 when the timer control requires such swing.

Referring now to the clamping device 22, as best seen in Figs.,2 and 3, it may comprise a plurality of individual clamps spaced transversely across the length of a cross shaft 35 which in turn is non-rotatably supported by brackets-36 fixed to an angle member 37 secured to side walls 38 or to the frame structural members. Collars 39 and 40 pinned on shaft 35 prevent endwise movement of clamp arm 41, and collar 40 holds one end of a torsion coil spring 42, the other end being secured in the hub 41a of the clamp arm 41 whereby to bias the arm counterclockwise, Fig. 2. A lug 41b on arm 41 carries an adjusting screw 43 which serves as a stop for the clamp arm when in disengaged position. The operating end of arm 41 carries a roller 44.

When the folding arm, carrying blade 19, swings rearwardly to the Fig. 2 position, the roller 44 rides along the portion of the workpiece which is draped on blade 19 with just enough pressure to hold the workpiece from slipping. When the three-quarter fold line drops horizontally opposite the edge 19a of the blade the timer means actuates the cam mechanism and blade 19 swings forward, to the left in Fig. 2. This movement tucks the superposed one-quarter-three-quarter fold lines between rolls 17 and 18. Fingers 46a on a sheet metal plate 46 extend into spaces between the rubber rings 17a and 18a, such fingers extend-ing through to the opposite side, as indicated in Fig. 1 so as to constitute a guide to direct the folded workpieces onto a slide 47 which carries them to a table or other collection point. The folding blade 19 has notch or finger portions 191; protruding from its leading edge 19a, these finger portions lying between the rubber rings so that the blade is not caught and held by the bite of the rolls.

The blade and supporting arms may be formed from It therefore is easily movable to frontward and rearward positions. The spring 27 snaps it forward when the cam rise recedes, by rapid 180 degree rotation. The next 180 degree rotation of the cam snaps the blade rearwardly by positive cam action. The clamp roller 44 has a smooth rolling contact with the blade top, and this has no appreciable effect on blade mot-ion. The clamping action is in a direction normal to the work supporting surface of the blade which gives rise to the least possible amount of frictional drag.

What I claim is:

1. In a folding machine wherein a pair of coacting rolls is provided to receive therebetween from folding means a preliminarily folded fiatwork article, in combination, means for delivering said article downwardly in a vertical plane, an elongated folding blade alternately swingable rearwardly away from said rolls at a first timed period and forwardly towards the bite of said rolls at a second timed period, and adapted to intersect said plane at each such rearward and forward swing, whereby, on

its rearward swing, to intercept and carry thereon a leading portion of said article, and on its return forward swing to intercept and carry thereon a trailing portion of said article, and clamp means carried by said folding machine adjacent the limit of rearward swing of said blade, said clamp means including an arm pivotally mounted on an axis substantially parallel to the axis of swing of said blade, a roller on the swingable end of said arm, the arc of travel of said roller intersecting the arc of travel of said blade whereby upon swinging movement of said arm said roller makes rolling contact with the upper surface of said leading portion of said article carried on said blade to thereby grip said article to prevent slippage thereof with respect to said blade.

2. In a folding machine wherein a pair of coacting rolls is provided on the machine frame to receive therebetween from folding means a preliminarily folded fiatwork article, in combination, means for delivering said article downwardly in a vertical plane, an elongated folding blade alternately swingable rearwardly away from said rolls at a first timed period and forwardly towards the bite of said rolls at a second timed period, and adapted to intersect said plane at each such rearward and forward swing, whereby, on its rearward swing, to intercept and carry thereon a leading portion of said article, and on its return forward swing to intercept and carry thereon a trailing portion of said article, and clamp means carried by said machine frame adjacent the limit of rearward swing of said blade, said clamp means having a pivotally mounted arm, and a roller carried by a swingable end of said arm, the arc of travel of said roller intersecting the arc of travel of said blade, biasing means urging said arm towards said blade whereby to cause said roller to make rolling contact with the upper surface of that portion of said article carried on said blade during its rearward swing, to thereby grip said article between said roller and said blade to prevent slippage of said article.

3. In a folding machine wherein a pair of coacting rolls is provided on the machine frame to receive therebetween from folding means a preliminarily folded fiatwork article, in combination, means for delivering said article downwardly in a vertical plane, an elongated folding blade having a generally planar upper surface alternately swingable rearwardly away from said rolls at a first timed period and forwardly towards the bite of said rolls at a second timed period, and adapted to intersect said plane at each such rearward and forward swing, whereby, on its rearward swing, to intercept and carry on said upper surface a leading portion of said article, and on its return forward swing to intercept and carry thereon a trailing portion of said article, and clamp means carried by said machine frame adjacent the limit of rearward swing of said blade, said clamp means having a swingable arm pivoted on said machine frame, a roller carried on the end of said arm remote from said pivot, the arc of travel of said roller intersecting the arc of travel of said blade, biasing means urging said arm towards said planar surface of said blade whereby said roller contacts the upper surface of the portion of said article on said planar surface during the time when said folding blade is adjacent its rearmost position, said biasing means and said pivot being so disposed that the clamping action of said roller is substantially normal to said planar surface.

References Cited in the file of this patent UNITED STATES PATENTS 776,837 Hallberg Dec. 6, 1904 1,216,773 Campbell Feb. 20, 1917 1,776,790 Mayer June 24, 1930 2,464,823 Mallot Mar. 22, 1949 

